Loose player opens in middle position. I am in late position with something like A2xx.

Scenario 1. It folds around to me. What 3rd cards should I keep? For example.. should I fold 8 or higher? Is it an easy call with just A2? If so, what two card hands should I play here? Am I raising all three card hands (that i plan to play) and smooth calling two card hands?

Scenario 2. Average player smooth calls. What kind of hands should I call with? What kind of hands should I raise with?

Scenario 3. Tight aggressive player raises. Should I fold all three card hands here to 3 bets? Seems like an easy fold because I am never far ahead and often behind.

Scenario 3: You hold A2xy, loose player opens, tight player reraises, you have position.

The question is, what will the tight player raise here? His range is certainly not limited to badugi. All he needs to reraise, and attempt to shut out the competition, is a smoother 3-card hand than what the loose player is likely to have. 3-card vs. 3-card heads up competitions are extremely profitable for the smoother hand.

Given that his range includes 3-card hands at all, it is much more likely than he has a 3-card hand than that he has a badugi. So, you should be willing to play 3-card hands as well.

32A, 42A: Keep, possibly put in the third raise. You don't mind convincing the loose player to fold, as you have the best shot of winning his two bets in the heads-up competition. You probably have the best hand at this point.

52A: You will lose depressingly often to a three-card four when you don't improve, but I think these are very playable.

62A: This is starting to look a bit worse. You can play if you think the 3-better's range includes rougher 6's, or if the loose player will pay off generously. But folding may be OK; you will not win many showdowns unimproved.

[I would probably play but I'm usually way too loose.]

72A: Nope, this one sucks.

I will work out a "probability of three card draws" table at some point and see how well my guesses here correspond to reality in terms of best starting hand %'s.

P.S. Bare A2 is playable "sometimes". You want a multiway pot or a cheap draw. A2 can be better than something like 678.